Labial approximant is the name of a class of consonants. Subclasses Labio-velar approximant, a consonant sound written as in the International Phonetic Alphabet Voiceless labio-velar approximant, a consonant sound written as in the International Phonetic Alphabet Bilabial approximant, a consonant sound written as in the International Phonetic Alphabet Labiodental approximant, a consonant sound written as in the International Phonetic Alphabet Labialized palatal approximant, a consonant sound written as in the International Phonetic Alphabet Consonants